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BROWN ROOT DISEASE OF PARA RUBBER. 



( Hymenochaete noxia, Berk/ 



By Keith Bancroft, b.a., Assistant Mycologist, F.M.S. 



A root disease of Para Rubber which has been for some time 

 known in Ceylon under the name of" brown roof disease," ^ has been 

 recently brought to the notice of the Department of Agriculture, 

 F.M.S. 



The fungus, Hymenochaete noxia, the cause of the disease, was 

 discovered by Rev. T. Powell in Samoa in 1875, on a species of Artocar- 

 pus. In 1905, it was reported in Ceylon on Hevea, Tea, Dadap, Cacao, 

 Castilloa elastica and Caravonica Cotton ; since then it has also been 

 found on Camphor {Cinnamomiim Camphora), Cinnamomitm Cassia, 

 Cacao and Bnmfelsia americana. It is said to be the comm.onest root 

 disease of Hevea in Ceylon. In the early part of 1910, specimens of 

 the fungus were sent to Kew from West Africa, where the fungus was 

 said to be doing some considerable damage to Cacao. The fungus 

 has also been recorded in New Guinea. 



A disease, which, from its symptoms, appears to be the " brown 

 root disease," was mentioned by Mr. Gallagher in Bulletin No. 2, 

 1909, Department of Agriculture, F.M.S., as occurring in this country 

 on Hevea and on Camphor ; the fungus was, however, not identified. 

 Mr. Ridley; mentions the report of the disease from Apia and states 

 that he has observed a species of Hymenochaete on Para Rubber in the 

 Malay States. 



The fungus was first recorded by the author on roots of Camphor 

 (Cinnamomiim Camphora in the Experimental Gardens at Kuala Lum- 

 pur, where a -number of plants were attacked. More recently it has 

 been reported on Hevea from some estates in Negri Sembilan. In the 

 plantations it appeared to be fairly common in certain areas although 

 on the whole in this country it is by no means so common as the 

 disease caused by Fomes semitostiis. 



Symptoms. 



When a tree is attacked the symptoms above ground do not differ 

 in any respect from those of the root disease caused by Fomes semitostus 

 or from the ordinary symptoms of root disease generally, i.e., the 

 leaves wither and death occurs rather suddenly. An examination - of 

 the roots shows the presence of well-marked symptoms v.^hich charac- 

 terise the disease. They are encrusted with a mass of earth and 

 small stones which are cemented to the surface of the roots by the 

 mycelium of the fungus. This can be found to occur more especially 

 on the tap root. The surface of the roots becomes dark brown and 

 almost black ; for this reason the disease is known to the coolie as 

 sakit hitam." 



t Fetch: Circulars and Agricultural Journal, Royal Botanic Gardens* Ceylon; Vol.. V., .. 

 No. 6, 1910. 



X Ridley: Agricultural Bulletin, S.S. and F.M.S , July, 1909. 



